Explanation of the Damage to the Royal Family’s Cemetery in Historic Cairo and Examination of the Building Materials

The cemetery of the royal family, who ruled Egypt from 1805 to 1952, is one of the masterpieces of the UNESCO World Heritage Site of Historic Cairo. It is a complex building from massive stone masonry walls supporting hemispherical domes and is very rich with the marble decorative elements. Unfortunately, it suffers nowadays from serious cracking due to on-going structural damage. Almost all the structural elements are cracked. Besides, the continuous rise in the groundwater table affects both its structural stability and aesthetics. A detailed inspection was carried out to identify and explain all the manifested damage by the structural elements of the cemetery. The differential settlement damage was found to be very noticeable in the form of many diagonal cracks that are active and threaten the overall stability of the cemetery. The construction history was investigated and found to have a clear effect on the noticed damage. Examination of the construction materials and deterioration products was carried out by inspecting representative samples of the stone, the marble, the mortar, the plaster and the salt. They were examined using different analysis techniques including the Polarized Microscope, the Stereo Microscope, the X-Ray Diffraction (XRD), and the Scanning Electron Microscope (SEM) provided with Energy-Dispersive X-ray spectroscopy (EDX) unit. This examination helped in identifying the type of the used stone, the mortar components, the types of salts affecting the structure, and the deterioration manifested by the marble. It seems that the cemetery needs an urgent conservation project to stop the deterioration and keep it safe for the next generations.